NEXAFS and MS-AES spectroscopy of the C 1s and Cl 2p excitation and ionization of chlorobenzene: Production of dicationic species. Issue 48 (7th December 2021)

• Record Type: Journal Article
• Authors: Coutinho, Lúcia H.; de A. Ribeiro, Fabio; Tenorio, Bruno N. C.; Coriani, Sonia; dos Santos, Antonio C. F.; Nicolas, Christophe; Milosavljevic, Aleksandar R.; Bozek, John D.; Wolff, Wania
• Is Part Of: Physical chemistry chemical physics. Volume 23:Issue 48(2021)
• Page Start: 27484
• Page End: 27497
• Publication Date: 2021-12-07
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/d1cp03121j
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : Dications formation following excitation and ionization of chlorobenzene. Abstract : We report on single- and double-charge photofragment formation by synchrotron radiation, following C 1s core excitation and ionization and Cl 2p inner excitation and ionization of chlorobenzene, C6 H5 Cl. From a comparison of experimental near-edge X-ray absorption fine structure spectra and theoretical ab initio calculations, the nature of various core and inner shell transitions of the molecule and pure atomic features were identified. To shed light on the normal Auger processes following excitation or ionization of the molecule at the Cl 2p or C 1s sites, we addressed the induced ionic species formation. With energy resolved electron spectra and ion time-of-flight spectra coincidence measurements, the ionic species were correlated with binding energy regions and initial states of vacancies. We explored the formation of the molecular dication C6 H5 Cl 2+, the analogue benzene dication C6 H4 2+, and the singly charged species produced by single loss of a carbon atom, C5 H n Cl + . The appearance and intensities of the spectral features associated with these ionic species are shown to be strongly site selective and dependent on the energy ranges of the Auger electron emission. Unexpected intensities for the analogue double charged benzene C6 H4 2+ ion were observed with fast Auger electrons. The transitions leading to C6 H5 Cl 2+ were identified from the binding energy representation of high resolution electron energy spectra. Most C6 H5 Cl 2+ ions decay into two singly charged moieties, but intermediate channels are opened leading to other heavy dicationic species, C6 H4 2+ and C6 H4 Cl 2+, the channel leading to the first of these being much more favored than the other.